Transferring reagents to, from, or between vials—a process commonly referred to as “pipetting”—is a basic function for most life science and chemical labs. Vials, also called “tubes” or “wells,” can be small and are commonly arrayed in considerable numbers. Pipetting large numbers of samples is repetitive and prone to human error. Unfortunately, such errors can result in grave consequences, especially in clinical diagnostic and forensic labs.
A number of companies have commercialized semi-automated pipetting tracking devices to reduce pipetting errors. For example, some pipetting systems position arrays of wells over similar arrays of visible light-emitting diodes (LEDs) to selectively illuminate the wells from beneath. Other systems employ an LCD screen in lieu of an array of LEDs for the same purpose, as detailed in U.S. Patent Publication No. US 2006/0188406 to James Dahle Frost III. Users of such devices can use this lighting to keep track of which wells will be subjected to the next pipetting step. These systems require the user to select an illumination pattern specifying a pipetting order. The user then manually advances to a next well or set of wells after each pipetting step, or advances to the next well or set of wells responsive to a preset timer. The manual step can include pressing a button, a foot switch, or passing a sensor outside the pipetting zone. These manual steps add to the workload and are also subject to human error.